* Make Python StackReference test similar to others (with two steps) * Include new Python StackReference integration test that uses multiple stacks * Expose various life cycle methods for ProgramTester
We don't actually depend on anything right now because all of these tests just depend on `pulumi` which is installed as an editable package.
This commit adds StackReference to the Python SDK, which uses read_resource to read the remote state of a a Pulumi stack.
